add openvr support, switch to 8.1 sdk, prepare for vr ui

src/hmd.h

@@ -0,0 +1,73 @@
+#pragma once
+#include "rtt.h"
+
+struct Controller
+{
+    enum class Button : uint64_t
+    {
+        Trigger = 0x200000000,
+        Pad = 0x100000000,
+        Menu = 0x000000002,
+        Grip = 0x000000004,
+    };
+    enum class Action
+    {
+        Press,
+        Release,
+    };
+    int index = 0;
+    bool active = false;
+    std::map<uint64_t, bool> buttons;
+    uint64_t buttons_bits{ 0 };
+    glm::vec2 axis[5];
+    glm::mat4 xform{ 1 };
+    glm::vec3 pos{ 0 };
+    glm::vec3 rot{ 0 };
+    vr::VRControllerState_t state;
+    bool valid = false;
+    int role = 0;
+
+    void update(const glm::mat4& m)
+    {
+        xform = m;
+        pos = glm::vec3(m[3]);
+        //float sx = glm::length(glm::vec3(m[0]));
+        //float sy = glm::length(glm::vec3(m[1]));
+        //float sz = glm::length(glm::vec3(m[2]));
+        glm::extractEulerAngleXYZ(m, rot.x, rot.y, rot.z);
+    }
+
+};
+
+struct Vive
+{
+    int comp_attempts = 0;
+    uint32_t eyeWidth = 0, eyeHeight = 0;
+    RTT eyes[2];
+    vr::IVRSystem* hmd = nullptr;
+    vr::IVRCompositor* comp = nullptr;
+    glm::vec3 euler{ 0 };
+    glm::vec4 background{ .5, .2, .2, 1 };
+    float yaw_offset = 0;
+    glm::mat4 view[2];
+    glm::mat4 proj[2];
+    glm::mat4 pose;
+    Controller controllers[32];
+    Controller trackers[32];
+    bool swap_controllers = false;
+    std::string dev_serial{ "0000001" };
+    std::string dev_model{ "Vive" };
+    std::string dev_tracksys{ "lighthouse" };
+    std::string dev_manufacturer{ "HTC" };
+    std::function<void(const glm::mat4& proj, const glm::mat4& view)> on_draw = nullptr;
+    std::function<void(const Controller&, Controller::Button, Controller::Action)> on_button = nullptr;
+
+    Vive();
+    bool Initialize();
+    void Terminate();
+    void ResetYaw();
+    void Draw();
+    bool Valid();
+};
+
+